Have you heard the one about the doting girlfriend who gave her heart to a guy for three years, only for him to say that he's not the marrying kind? And then when they break up, he turns around and proposes to some bitch (and we do mean bitch!), three months later.

"I see it all the time," confesses Randi Gunther, PhD, couples counselor, and author of the upcoming book Relationship Saboteurs (June 2010). "Women know they have the capacity to nurture and care for men, and will be extremely giving. The problem is when a woman holds it against her partner — as if she's a martyr — and the guy suddenly feels very guilty and, even worse, obligated. A man likes a bitch because she has her own agenda that isn't all about him; he likes that he's not totally responsible for her happiness."

If you enjoy being a giving person, then by all means, keep it up. Just understand that it's like putting money into a bank that has a hole on the bottom — you can't expect to cash in (say, like for a commitment from a guy). Do nice things because you want to — and don't forget to be a little selfish too.

2. You Overcommunicate

With all the Facebooking, tweeting, IMing, e-mailing, and texting going on, it might feel impossible to not communicate a lot with your boyfriend or husband, at least indirectly. But all that extraneous info about what you're doing dissolves your alluring mystery, warns Ian Kerner, PhD, sex therapist and author of She Comes First.

"I actually defriended my wife on Facebook," he admits. "We've all heard the phrase that familiarity breeds contempt, but in this age of social networking, perhaps familiarity breeds something worse: boredom."

Keep some of your mystery — and mask your mundane day-to-day life — by resisting the urge to check in with your guy constantly. And ditch all the dumb updates about what you had for breakfast. We promise you that No. One. Cares.

3. You Air All Your Frustrations to Your Friends

Admit it: A good venting sesh with your girls feels great. You get to rant about how you think your man was checking out another girl last Saturday, or how you can't believe he wants to buy a new car when he could be saving that money for an engagement ring. But constantly telling your friends your guy gripes — even the smallest stuff — can sabotage your relationship, says Gunther.

"Your friends want to support you, will sympathize with you, and won't challenge you," explains Gunther. "So then everyone comes away from the chat with the deep opinion that your boyfriend or husband is usually in the wrong."

All your bitching and moaning can have a lasting effect on how your friends feel about your guy, and eventually they'll stop supporting your relationship because they remember every last jerky thing he's done. Not good. So, bottom line? You don't have to cut the chick chat altogether…but tone it down, and be sure to tell them about the nice things he does every once in a while too. You'll feel much better about your relationship overall if you remind yourself from time to time that he's a good guy.

Keep reading to find out the last two surprising, "harmless" things you might be doing wrong…

4. You Don't Think You're Hot

Do you have a hard time accepting compliments about your body? Freak out at the thought of your guy watching you walk butt-naked to the bathroom? Cringe anytime your guy grazes his hand across your stomach? These seemingly minor habits could be more dangerous than you realize because poor self-esteem about your body can damage your sex life, warns Kerner.

"If you don't feel sexy, you're just not as interested in having sex," says Kerner. "Or maybe you only want to do it with the lights off or leave some of your clothes on. Many men I work with are very frustrated because they think their girlfriends and wives are beautiful, but the women are very inhibited."

To keep your insecurities from hurting your relationship, the first thing you have to do is take your body-bashing down a notch. Stop pointing out your flaws to your guy — you don't want him to start believing what you're saying, do you? It's easier said than done, but start making the transition by incorporating confident little changes in the bedroom. Even if you really don't want the lights on, try lighting a few candles instead. After all, everyone looks good in candlelight!

5. You Confuse Hopes with Realistic Expectations

Have you ever fantasized about your boyfriend doing something special — say, throwing a surprise birthday party for you — and then thought about it so much that when it didn't happen, you were genuinely disappointed? Maybe you even got a little mad that all he did was get you a cupcake and sweater from Express. This kind of behavior can wreak havoc on your bond.

"You can't walk into a relationship with a script," says Gunther. "A lot of us have neurotic expectations, but are so invested in our fantasies that we keep going back to them. It's fine to hope for certain things from your man, but they need to be based on some realistic potential of actually being satisfied."

In other words, if your boyfriend never plans weekend getaways, stop disappointing yourself by daydreaming that he'll whisk you away to a B&B. It's fun to have fantasies, but if they're causing constant disappointment in your relationship, you're just setting yourself up to fail. Focus on the stuff your guy does right (rather than what he's not doing), and you'll strengthen — not sabotage — your love connection.